Mercedes’ perennial S-Class limo used to categorically rule the roost in the executive car class, but within the last few years, its competition has crept ever closer to swiping class honours.

We hailed the all-new Audi A8 as a feast for tech fans, and the big barge from Ingolstadt was a surprisingly good steer – but that doesn’t mean the Sonderklasse has been left behind.

In order to keep it on top, Mercedes has tweaked the S-Class for 2017, with our first experience of the facelifted car coming in the shape of the ballistic AMG 63 and 65 models. There’s way more to the swish limo’s repertoire than some burly V8-ness, though.

Now we’ve gotten to grips with the volume seller in the line-up in long-wheelbase format, with impressions from both the drivers’ seat and as a passenger.

Wait, there was a facelift?

There was in summer 2017 but it was more about subtle refinements to the recipe than massive whitewashing changes. The headlines are a range of new straight six engines to the non-AMG versions, the ‘Energising Comfort’ system that modifies the music, ambient lighting – and even fragrance to alter the mood of those inside as well as upgrades to the assistance tech.

The adaptive cruise is now operated via buttons on the wheel rather than Mercedes’ usual stalk-based method and reacts to junctions, roundabouts and toll booths by changing the speed.

Your only real visual differences are the new headlight clusters, which now have a three-stroke daytime running light effect rather than a single line.

What’s the interior like?

Inside the sumptuous cockpit, the driver is cocooned by a huge swooping dashboard with a one-piece veneer of two massive, crisp information screens, and hugged by well-padded and well-upholstered leather armchairs. The fact that they have massage functions means you’ll easily go cross-eyed with ecstasy behind the wheel.

Speaking of the wheel – it’s a new version that’s bit more contemporary than the two-spoke one offered previously, and now houses the cruise control settings and a smorgasbord of various other functions.

The infotainment is controlled by the standard Mercedes COMAND controller with scroll wheel, touchpad and steering wheel interfaces. Navigation input can be a little clunky if you’re using the scroll wheel, mind, and the sheer number of systems meant that the infotainment lagged a little now and then.

It would be preferable not to be choked by the pretensioner every time you put your seatbelt on, and a little more reach adjustment for the steering wheel would be greatly appreciated for a lanky fellow, too.

The L is a big car…

An astute observation, Captain Obvious. A long-wheelbase executive car isn’t exactly going to be the most wieldy of machines, so unless you’re on the open road, prepare yourself for how far the bonnet stretches when you’re crawling through a traffic jam. You may also have to resort to the 360-degree parking cameras to squeeze through width-restricted roads or multi-storey car parks without dinging the precious paintwork or kerbing a wheel.

Even when you’re in a parking bay, you won’t completely fit in it. Parallel parking? Chances are the S-Class is too wide. In an end-on bay parking? You’ll stick out by about a foot, so good luck with that. The hands-free parking does its best, but even it struggles to squeeze into regular-sized parking spaces without some kind of overhang.

What’s it like to drive, then?

Power comes from a new 3.0-litre straight-six diesel engine, pumping out 282bhp and 443lb of torque to the rear wheels through a nine-speed automatic gearbox. Even though this is an almost two-tonne car, it still shifts; a 6.0-second 0-62mph launch time is enough to get your diplomat passengers out of the UN faster than you can say ‘delegation’ and speed is electronically limited to 155mph.

In terms of refinement, the S350d is on a whole other level. The engine only becomes vocal if you really poke it, but it’s such a muscular and tuneful six-cylinder note that it’s often welcomed. Meanwhile, the gearbox tasked with handling the power is so unobtrusive that you wonder if there’s even one there at all half the time, chopping and changing between any of the nine ratios with silky-smooth ability.

Even at motorway cruising speeds, it’s so quiet all you can hear is a faint hush from the tyres and the motors in the massage seats working away. Spooky stuff, but eminently relaxing.

It’s a car you drive as if you’re not in any hurry; instead you’re there to take full advantage of the radar-scanning active body control and torquey engine. If we had to point out a negative, the steering is a little too light in its normal setting – we’d like a bit more heft to the inputs – but all in all wafting around in the Sonderklasse is still a memorable and luxurious experience.

How about as a passenger?

‘I’ve never felt more comfortable in my life.’ How about that for a direct quote?

Our stint with a car included a day trip from Newcastle to Edinburgh and back with family member passengers taking full advantage of the rear space. Our S350d test car came with the optional Individual Rear Seat pack, which makes the S-Class a four-seater rather than the usual five and includes backrests that recline up to 37-degrees, ‘luxury’ headrests, folding tray tables and temperature-controlled cupholders.

That wasn’t all, our rear passengers got to experience heated, cooled and massage-enabled seats and could tweak almost everything about the car from the remote-controlled screens in front of them. It was so entertaining to hear so many shocked ‘wow’s and relaxed sighs from two people who have absolutely no interest in cars.

In short, it’s a better place to be than behind the wheel.

Verdict

Why you’d need anything more than an S350d is a little beyond reason, frankly. It’s extremely quiet and comfortable, has as much power as you could ever really need, is filled to the brim with technology but isn’t showy. Just what a captain of industry deserves and requires.

The long-wheelbase version is a better car to be driven in than drive yourself, but it would make an excellent addition to the fleet an executive chauffeuring firm – especially if you choose all of the optional goodies that make full use of the extra space. Even so, those tasked with helming this business class jet for the road will not be disappointed by the experience.